In an array of solar cells used as the power source for a device such as a clock, a wristwatch, an electronic calculator or the like, it is generally the case that only a limited area is available in which solar cells can be exposed to the light. Thus, it is essential that the active area of the cells utilize the available area as nearly completely as possible. Consequently, the space consumed by insulative materials separating adjoining cells must be minimized.
Conventionally, solar cells are placed together as closely as possible without incurring substantial danger of making contact between adjoining cells and thus developing a short which will limit the output of the array. Moreover, in order to make maximum utilization of the space available, the cells must be placed in some sort of orderly configuration. With rectangular cells, the configuration will be essentially rectangular. For a circular array, the cells are conveniently sectorial in shape. Up to now, conventional techniques have made it essentially impossible to decrease the separation between cells below about 0.3 mm, even where the individual carrying out the fabrication is of the highest skill. A separation of this magnitude, as indicated by the discussion up to this point, involves a serious waste of the available area. In addition, the gap between the solar cells is relatively conspicuous and where the cells are to be used in a device such as a lady's wristwatch, the gap between the cells constitutes an eyesore. The same holds true, though, perhaps to a lesser extent, whenever a solar battery is to be used in ornamental goods such as clocks and wristwatches for men.
As is evident, it would be desirable to improve methods of fabrication so that solar batteries could be made available which utilize virtually all of the space provided and which do not suffer from the defect of conspicuous gaps between adjoining cells.